It's a field solver that uses Maxwell's equations.  There is no simple
equation into which you can put line width,  thickness, etc.  You have
to build the structure (in 2-D) you are interested and then invoke the
solver.  It handles single-ended and differential impedance.  You can
build coplanar ground structures and simulate ground vias.  We've used
it for a few years and found that it's very accurate IF you have the
right inputs, especially the right dielectric constant at the right
frequency.  The user interface is not as good as some of the other
simulation program's I've seen, but it's also not as expensive.

        ----------
        From:  Ken Patel [SMTP:[log in to unmask]]
        Sent:  Friday, August 27, 1999 3:36 PM
        To:  [log in to unmask]
        Subject:  [TN] Impedance Modeling by Applied Simulation
Technology

        Does anybody know about Applied Simulation Technology ApsimRLGC
software
        used for Impedance Modeling? Can anyone provide me the equation
this people
        uses to calculate Microstrip & Stripline impedance and
capacitance calculation?

        I suppose this is not a confidential information.

        re,
        ken patel
        ______________________________________________________
        Ken Patel                       Phone:  (408) 490-6804
        1708 McCarthy Blvd.             Fax:    (408) 490-6859
        Milpitas, CA 95035              Beeper: (888) 769-1808

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